I really like the combo
The question I haven't seen an answer to is, what about the sound of your system would you like to improve by changing amplifiers and/or speakers? IMO, McCormack amps sounded good in stock form. Your Revision A Gold should have improved on the stock amp considerably.
However, McCormack upgrades are not for everyone. They do cost money, so the question you have to ask yourself is, "what could I purchase new or used for the same all-in cost?" In addition, the upgrades take time. Steve and Patrick do their best but they have a lot of customers and the process is staged, with some of the work relying on others to complete, like powder-coating chassis, ordering key parts like the low-noise transformers they use, ordering custom faceplates, and other steps in the process. Finally, those who say you will lose much of the upgrade cost on resale are mostly correct, which means you should do everything you can to figure out what you want and whether the upgraded McCormack amplifier is likely to provide it. If you don't like the sound of your McCormack amp now, an upgraded version is probably not going to be much better for you. However, if you already like the house sound but want improved refinement, lower noise, improved high frequency clarity, improved bass definition, and more depth/dimensionality, then the upgrades should push you further towards your goal. Some options can have a significant impact on the level of improvement, such as going from a single amplifer to monoblocks or installing the much larger low-noise transformers in the DNA 0.5s.
As expensive as my upgraded SMc monos were, they provide sound quality from my system that I had previously not achieved at anywhere near the price, including monoblocks from well-regarded manufacturers priced at about $17K (new) for the Claytons (upon their last issue) and about $34K (new) for the Lamm amps (current pricing). Some might even say the SMc amplifiers are a bargain.